The word ‘thermogenic’ means ‘tending to produce heat’. Thermogenic supplements can help you create heat by stimulating your metabolism. Most reactions in your body that involve enzymes are thermogenic and they help to increase your basal metabolic rate.
Your body will generate heat whenever it uses calories, therefore substances that accelerate your metabolism or help burn fat are regarded to be thermogenic.
Reported Benefits of Thermogenics
They Can Help You Burn Fat
The principal benefit of thermogenics is that they can help you burn fat and also enhance your body composition if you use them properly. You still need to make sure that you stick to a balanced diet, though, and also that you maintain a disciplined exercise regime.
They Can Reduce Your Appetite
Some thermogenic ingredients can help to suppress your appetite. This means you are likely to eat less and burn off more calories than you take in. Taking a supplement to curb your hunger can really help with this.
They Can Give You More Energy
Thermogenic supplements can also boost your energy levels. This boost can help you maintain enough energy to enable you to still perform an intense workout, even though you’re keeping to a calorie-controlled diet.
One clinical trial demonstrated that when subjects took a commercially available thermogenic supplement, their energy output increased substantially. The trial was conducted applying benchmark fitness tests such as respiratory quotient and resting oxygen uptake. (1)
They Can Enhance Your Focus
There is also evidence that some thermogenic supplements may boost your concentration and focus. Improving your cognitive performance can, among other things, heighten your ability to exercise at a greater intensity.
Common Ingredients Found in Thermogenics
Bitter orange, also known as citrus aurantium, contains synephrine, Synephrine is a natural stimulant which is related to ephedrine.
Due to reports of cardiac-related fatalities, the United States have banned ephedrine. However, experts have determined that synephrine has much milder effects and is a safe ingredient to include in thermogenic supplements.
If you take 50mg of synephrine per day, research has shown that it can substantially accelerate your metabolism and help you to burn through an extra 65 calories per day.
In one clinical study, researchers found that participants taking bitter orange experienced a substantial increase in metabolism and ability to lose weight when they took it once a day for a period of six to twelve weeks. (2)
Caffeine works by boosting your adrenaline levels. Adrenaline is the hormone that induces your fat cells to release fatty acids into your bloodstream. Your cells can then use these fatty acids for energy.
Additionally, caffeine can suppress your appetite and accelerate your metabolism. Consequently, this will help you eat less and use up more calories.
Experts have discovered that every milligram of caffeine you take can help you burn an extra tenth of a calorie for the subsequent 24 hours. For example, if you took a 150mg caffeine pill it would help you to use up 15 more calories during a period of one day.
Research has also shown that the optimum dose of caffeine is 3–5 mg per kg of body weight for fat-burning and metabolism. (3)
Capsaicin, like caffeine, also helps to increase your adrenaline levels, stimulating metabolism and calorie-burning. It can also curb your appetite, and consequently, your calorie intake. All in all, capsaicin is quite a potent thermogenic supplement.
Capsaicin can accelerate your metabolism by as much as 50 calories per day, researchers have discovered. Correspondingly, it can substantially help you with weight loss.
A clinical trial was conducted in which subjects took 2.5mg of capsaicin with every meal. Results showed that in the subsequent 24-hour period, they burned 10% more fat than participants who took no capsaicin. (4)
The tropical fruit, garcinia cambogia contains hydroxycitric acid (HCA). This works to suppress the function of citrate lyase, an enzyme which helps to create body fat.
If you take garcinia over a period of two to twelve weeks it can help you lose up to 1% more of your bodyweight, researchers have demonstrated. (5)
Green Coffee Bean
Green coffee beans contain the active ingredient, chlorogenic acid. Chlorogenic acid helps your body to prevent carbohydrates being absorbed from your digestive system. It can also help you decrease both visceral fat and levels of the hormones that cause obesity. Consequently, this helps reduce your body weight.
Green tea contains caffeine and also epigallocatechin gallate (EGCG), which is also a particularly effective thermogenic.
Caffeine stimulates the release of adrenaline, as outlined above. EGCG helps to amplify the thermogenic effects by decelerating your body’s breakdown of adrenaline.
Green tea supplements can accelerate your metabolic rate by as much as 4% and help you burn up to 16% more fat for up to 24 hours after taking them. This has been verified by research.
One clinical study discovered that when participants consumed a green tea supplement for 12 weeks, they achieved an average weight loss of 1.3kg, which was not dependent on the dose taken. (6)
The guarana plant, which originates in the Amazon, contains high levels of caffeine. In fact, guarana berries can contain up to four times more caffeine than you’ll find in coffee beans.
During a contemporary clinical study, researchers found that guarana is so effective at stimulating your metabolism, it can help you lose weight even if you’re eating too much fat in your diet. (7)
Side-Effects of Using Thermogenics
Most people will be fine taking thermogenics, but some may experience side-effects.
Most effects are minor but can be unpleasant, such as abdominal pain, constipation, headache, nausea and also, possibly, elevated blood pressure. (8)
In rare cases, some people may experience more severe side-effects, such as inflammatory bowel disease or liver failure.
Thermogenic supplements usually contain stimulants so it’s wise to start on the minimum recommended dosage. This way, you can assess your tolerance and adjust if necessary.
You should generally take them about half an hour before exercise to help you optimise your calorie burning. And you shouldn’t take them before bed because the stimulants can disrupt your sleep.
You shouldn’t exceed the recommended daily dose and it’s sensible to seek medical advice before taking thermogenics.
- ‘Effects of ingestion of a commercially available thermogenic dietary supplement on resting energy expenditure, mood state and cardiovascular measures’. Jordan Outlaw, Colin Wilborn, Abbie Smith, Stacie Urbina, Sara Hayward, Cliffa Foster, Shawn Wells, Rob Wildman, and Lem Taylor
- ‘A Review of the Human Clinical Studies Involving Citrus aurantium (Bitter Orange) Extract and its Primary Protoalkaloid p-Synephrine’. Sidney J. Stohs, Harry G. Preuss, and Mohd Shara
- ‘The effect of caffeine on energy balance’. Eynav Harpaz, Snait Tamir, Ayelet Weinstein, Yitzhak Weinstein
- ‘Acute Effects of Capsaicin on Energy Expenditure and Fat Oxidation in Negative Energy Balance’. Pilou L. H. R. Janssens, Rick Hursel, Eveline A. P. Martens, and Margriet S. Westerterp-Plantenga
- ‘The Use of Garcinia Extract (Hydroxycitric Acid) as a Weight loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials’. Igho Onakpoya, Shao Kang Hung, Rachel Perry, Barbara Wider, and Edzard Ernst
- ‘The effects of green tea on weight loss and weight maintenance: a meta-analysis’. R Hursel, W Viechtbauer, M S Westerterp-Plantenga
- ‘Guarana Provides Additional Stimulation over Caffeine Alone in the Planarian Model’. Dimitrios Moustakas, Michael Mezzio, Branden R. Rodriguez, Mic Andre Constable, Margaret E. Mulligan, and Evelyn B. Voura
- ‘Thermogenic ingredients and body weight regulation’. R Hursel , M S Westerterp-Plantenga